Textile strand splice and method of forming same



Aug. 19, 1969 M. F. IRWIN ETAL 3,461,661

TEXTILE STRAND SPLICE AND METHQD OF FORMING SAME I Filed May 16. 1968United States Patent i 3,461,661 TEXTILE STRAND SPLICE AND METHOD OFFORMING SAME Malcolm F. Irwin, Philadelphia, and Frederick J. E. Hampel,East Greenville, Pa., assignors to Techniservice Corporation, Lester,Pa., a corporation of Pennsylvania Continuation-impart of applicationSer. No. 645,410,

June 12, 1967. This application May 16, 1968, Ser.

Int. Cl. D06c 29/00 U.S. Cl. 57-442 8 Claims ABSTRACT OF THE DISCLOSUREMultifilament textile strands are spliced in an elongated chamber openat both ends and having a conduit for directing fluid, such as air andsometimes a resin, into the chamber to rotate circumferentially. Theresulting splice has substantially constant diameter throughout.

This application is a continuation-in-part of our copending application,Ser. No. 645,410, filed June 12, 1967, now Patent No. 3,407,583.Reference is also made to our prior copending application, Ser. No.609,463 filed Jan. 16, 1967 and now abandoned, of which theaforementioned application was itself a continuation-in-part.

This invention relates to splicing of textile strands composed of aplurality of filaments, i.e., principally multifilament strands,optionally having staple fiber components. The strands to be splicedtogether are overlapped, and the overlapped lengths are subjected tofluid rotating circumferentially thereof, which swirls the componentfilaments so that the strands will not be separated by applied tensions.Gun-like apparatus is provided by doing so and for applying an auxiliaryadhesive agent when desired.

There is a considerable need for a simple, reliable, and cheapstrand-splicing method to replace the old-fashioned method of tying andknotting, which has its own disadvantages, being conducive to snaggingand breaking of the strands in ordinary textile processing. Some methodsfor joining or splicing textile strands together utilize solvents oractually melt component filaments and are limited to thermoplasticstrands. Fluid jet methods whereby air or the like is blown at orthrough textile strands to entangle the component filaments have beendevised also. These and other splicing methods are either so complex asto be too costly or are unreliable in their operation or results orproduce an undesirable knot-like or other lump or enlargement at thesplice itself or in part of the splice.

A primary object of the present invention is provision of a method forair-splicing textile strands.

Another object is provision of gun-like apparatus for practicing thatmethod.

A further object is application of an adhesive agent to the splicedstrands.

Other objects of the present invention, together with means and methodsfor attaining the various objects, will be apparent from the followingdescription of a preferred embodiment and the accompanying diagrams.

FIG. 1 is a perspective view of an apparatus component useful accordingto the present invention;

FIG. 2 is a side elevation, partly in section, of apparatus of thisinvention including the component apparatus of FIG. 1 (sectionedtransversely) and showing two strands therein about to be joined;

FIG. 3 is an end elevation of two such strands on an enlarged scale;

FIG. 4 is a fragmentary side elevation of a portion of the apparatus ofFIG. 2, showing part thereof in alternative positions;

3 ,4 6 1,661 Patented Aug. 1 9, 1 969 FIG. 5 is a front elevation of theapparatus component of FIG. 1 with strands to -be joined in place;

FIG. 6 is a side elevation of a resulting splice of textile strands;

FIG. 7A is a sectional elevation (sectional shading omitted because ofthe small scale) through the splice talzien at 7A-IA on FIG. 6 on thesame scale as FIG. 3; an

FIG. 7B is a similar sectional elevation therethrough taken at 7B7B onFIG. 6.

In general, the objects of the present invention are accomplished by thesteps of juxtaposing the respective strands side by side, rotating fluidcircumferentially of the juxtaposed strand lengths and thereby swirlingthe component filaments from both of the strands into an inseparablestructure. The invention provides, as means for doing so, splicingapparatus comprising a tubular chamber, open at its opposite ends, witha slot extending one end to the opposite end and communicating with theexterior and with the chamber interior throughout its length, and havinga fluid inlet extending from the exterior to the chamber interiorbetween the ends.

FIG. 1 shows splicing chamber 11 in the form of a rectangularparallelepipedal block having longitudinal cylindrical bore 12 from endto end and slot 13 extending along the top from end to end andcommunicating with bore 12 throughout. Tube 14 fits into one side of theblock midway of its ends and nearer theslotted top surface of the blockthan the bottom, terminating essentially tangentially of the cylindricalinterior. Aflixed to the bottom and extending beyond the opposite endsof the block is strip 15, which has upstanding from each of its ends oneof a pair of clips 16 extending past the bore axis.

FIG. 2 shows, in side elevation and partly in section, splicer 10 ofthis invention including (in transverse section) chamber 11 of FIG. 1with two similarly sectioned strands 1, 1' shown at approximately thechamber axis. The strands are shown enlarged in FIG. 3, from which itcan be seen that each contains numerous individual filaments. The nearclip holding the strands outside the chamber is ahead of the sectionalview in FIG. 2 and, therefore, not seen; the further clip, whichnormally would be visible at the rear, is omitted in the interest ofclarity of the showing.

The splicer includes, in addition to the chamber and its attachments,gun 21 provided with intake fitting 22 at the base of grip 23. Supplyhole 24 for air or other fluid (preferably gaseous) medium is attachedto the intake fitting. Upper adjusting nut 25 limits the inflow of theair or other gas, which is initiated by depressing pivotally mountedtrigger 20. Also carried by the gun is liquid container 31, whichthreads at its top into cap 32 afiixed to intake fitting 33 on barrel 29of the gun. Lower adjusting nut 26 limits the inflow of liquid from thecontainer to be propelled through and out of the barrel by the air orother gas.

FIG. 4 shows trigger 20 of the splicer gun in three successivealternative positions: A (solid line), B (dotdashed line), and C (brokenline) corresponding, respectively, to the OFF position (no gas or liquidflowing), the BLOW position (gas only flowing), and the JET position(gas plus liquid flowing). Although the interior of the gun is notshown, a conventional paintspray gun may be used, in which the desiredaction and control are obtained by means of sliding valve elements whichprogressively move valve pistons (not shown) to uncover internal valvesin the gas and liquid intake lines successively, the degree thereofbeing determined by the setting of the respective adjusting nuts, whichvary the position or elfective length of the valve pistons.

In the practice of this invention, as will be apparent, a plurality(usually two but more can be used) of strands are juxtaposed by beingoverlapped for a length of at least as great as the spacing betweenclips 16 and are inserted through slot 13 in the top of the blockcomprising chamber 11 until they are received by the clips, which holdthe overlapped strand lengths along substantially the axis of bore 12,as in FIG. 5. With the strands thus in place the trigger is depressedfrom position A (OFF) to position B (BLOW) for a short time (such as afew seconds) whereupon air (or other suitable gas, such as carbondioxide or nitrogen) under pressure and optionally hot is injected intothe chamber from gun barrel 29 through interconnecting tube 14. Rotatedby the blast of gas so injected into the chamber, the juxtaposed strandlengths are swirled about to such an extent that filaments of eachbecome interengaged with filaments of the other, with the result shownin FIG. 6.

The resulting strand structure is unitary, with increased diameter,along much or most of the length of the chamber bore, as so muchinterengagernent of filaments occurs that the original strand identityis lost there. Thus, FIG. 7A shows (in somewhat stylized form) arepresentative transverse cross-section through the splice at a locationmidway of the chamber ends, showing the component filaments sectionedessentially end-on. The central plane, in which this view is taken, asindicated on the view of the spliced structure in FIG. 3, is also thelocus of maximum rotation by the jet. At this location the structure issomewhat looser than elsewhere in the splice, except at the ends,probably attributable to the fact that the filaments are essentiallystraight and parallel there where the induced twist (more properly falsetwist) in the strand reverses, more or less midway. The interstices atthis central location are especially amenable to take-up and retentionof adhesive when used. In FIG. 7B, which represents (similarly stylized)a representative transverse cross-section through the splice at alocation intermediate the central portion and the end, the structure isgenerally similar to that shown in FIG. 7A but differs therefrom inexhibiting more elongated or elliptical filament cross-sections, andconsequently somewhat reduced interfilament spacing, attributable totwist and interengagement of the component filaments. It will beunderstood that the relatively uniform stylization in representation ofthe individual filaments is merely an approximation and that in anactual splice greater variation in direction of major and minor axes inthe respective generally elliptical sections would appear because ofvariation in filament orientation and in angle at which the respectivefilaments intersect the plane of the cut. Sectional shading is omittedfrom both FIGS. 7A and 7B because of size limitations.

If greater splice security is desired, as with strands of relatively fewfilaments or otherwise, further manual depression of the trigger toposition C (JET) causes liquid resin to be atomized from container 31and to be propelled into the chamber by the flow of air or other gas andonto the filaments, especially at the intermediate (FIG. 7A) position,where it solidifies to retain them in their spliced configuration. Ifdesired, heat may be applied by any suitable means, as by a heating coilor infra red lamp (not shown) in the chamber, to cure the resin afterapplication. Suitable resins will be apparent to those persons havingordinary skill in the art and may be of readily availablemelamine-formaldehyde, ureaformaldehyde, or epoxy type, for example. Thesplice should be retained in place with the air turned off or nearly soto avoid disturbance of the filament configuration during curing orsetting of the resin. Hot air applied under low pressure at the BLOWposition can be helpful in that regard.

Whether a resin or other adhesive is applied or not, the splice isremoved from the chamber through the slot, and the unspliced ends ortails preferably are eliminated by cutting them off near their junctionwith the body of the splice. No special precautions are necessary inhandling the spliced strand during performance of normal textileoperations. The splicing process is quick and easy, and if desired thesplicing apparatus can be provided with automatic timing means (notshown), which may be adjustable for different splicing periods, as forstrands of dififerent composition, total denier, denier per filament,tension, or twist.

Unlike air-splicing methods of the prior art, the present invention isespecially useful in joining strands having appreciable twist therein,i.e., one or more of the strands having more than one turn and as muchas several turns or more per inch. During splice formation, at leastwhen the strands have a like direction of twist, the twist is backed outat least partially (and usually reversed) on one side from anintermediate locus or plane, and while it is tightened somewhat on theother side therefrom the result is formation of a secure splice, whichmay be a bit unsymmetrical longitudinally with respect to thatintermediate locus. When the twist in the unspliced strands is equal andopposite, the resulting splice is longitudinally symmetrical, i.e., thelocus or plane of twistdiscontinuity in the false-twisted spliceconfiguration is centrally located. Of course, the splicing process ofthis invention works as well on strands having little or no initialtwist.

Nor is it necessary to increase or reduce tension in the strands to bejoned, as untensioned strands may be treated at low fluid pressures orresulting velocities, and the flow may be increased in accordance withincreasing strand tension. It often is desirable to start the fluid flowat a low pressure or rate and to increase it markedly during theformation of each splice as the swirling action takes place. While uponcessation of the fiow the false-twisting action ceases, and upon releasefrom the splicer the induced false-twist is largely nullified, somethingof a twist-discontinuity usually remains at the intermediate locus inthe splice, and minor twist-discontinuities may occur at each end of thespliced portion as it tends to but cannot quite assume the twist (orlack of it) in the adjoining single strand lengths.

Unlike previous splicing methods, whether they relied upon solvent orthermal softening or air entanglement, the present invention does notproduce a relatively enlarged nub or knot-like structure at the centerof the splice but provides a splice having its intermediate ortwist-discontinuity (usually twist-reverseal) portion more nearly likethat of the starting strands. The component filaments at suchintermediate location are relatively parallel and although theynaturally tighten under tension they are as disengageable or relativelyloose under tension-free conditions as in the original strands underlike conditions. The splice diameter is substantially uniformthroughout. When resin or other adhesive is added it flows info theintermediate portion of the splice primarily, where it adheres andsolidifies, without forcing the filaments apart and so enlarging thesplice.

Other advantages and benefits of practicing the present invention inaccordance with the disclosure of a preferred embodiment andmodifications therein, as suggested, will be apparent. The respectivestarting strands cannot be reconstructed from the spliced structure evenin the absence of adhesive binding except by painstaking manualseparation of the individual filaments to permit restoration of them totheir original positions. Ordinary textile processing tensions will notseparate it into the two original strands either. Excessive tensions maybreak individual filaments or even all the filaments before separationof the splice itself.

The claimed invention:

1. In the air-splicing of a plurality of multifilament textile strandshaving appreciable twist therein, the improvement comprising rotatingair circumferentially about lengths of the respective strands juxtaposedside by side, thereby false-twisting at least part of the juxtaposedlengths thereof in opposite directions from a longitudinallyintermediate locus thereon and swirling filaments from each strand intointerengagement with filaments from the other strand at locationsflanking the intermediate locus.

2. The method of claim 1 wherein the false-twisting step forms atwist-discontinuity at the intermediate locus.

3. The method of claim 1 wherein the twist-discontinuity is atwist-reversal.

4. Textile strand splice of a plurality of multifilament strands, thesplice being characterized by substantially constant diameter throughoutand having an intermediate portion with a looser structure than theportions flanking the intermediate portion.

5. Textile strand splice according to claim 4, wherein the intermediateportion exhibits a twist-discontinuity.

6. Textile strand splice according to claim 5, wherein the portionsflanking the intermediate portion exhibit oppositely directed twist.

7. Textile strand splice comprising a plurality of multifilament textilestrands extending in opposite directions from portions of each strandconstituting the splice, with an intermediate portion of the splicebeing characterized by filaments of the respective strands extendingsubstantially straight and parallel to one another, and with portions ofthe splice flanking the intermediate portion being characterized byfilaments of each strand interengaged with filaments of each otherstrand 8. Textile strand splice according to claim 7, wherein at theflanking portions of the splice the filaments are in swirlingengagement.

References Cited UNITED STATES PATENTS 2,895,285 7/1959 Hilbert 57-34 XR2,985,995 5/1961 Bunting et a1. 57-140 3,262,179 7/1966 Sparling 57-34XR 3,339,362 9/1967 Dodson et a1. 57-159 3,274,764 9/1966 Gonsalves57-142 3,306,020 2/1967 Rosenstein 57-22 3,334,477 8/1967 Morin et al.

FOREIGN PATENTS 824,742 12/1959 Great Britain. 956,992 4/1964 GreatBritain.

DONALD E. WATKINS, Primary Examiner US. Cl. X.R. 57-159

